[Haskell-cafe] RE: TChan implementation: Why TVarList
The mutable cell is in the tail. A [TVar a] would be quite different. You can read about a very similar impl (based on MVars) in the original Concurrent Haskell paper (on my papers page) S | -Original Message- | From: Joel Reymont [mailto:[EMAIL PROTECTED] | Sent: 06 December 2005 11:28 | To: Simon Peyton-Jones | Cc: Haskell Cafe | Subject: TChan implementation: Why TVarList | | Simon, | | Why did you guys implement TChan on top of your own TVarList instead | of a regular list? | | -- | 'TChan' is an abstract type representing an unbounded FIFO channel. | data TChan a = TChan (TVar (TVarList a)) (TVar (TVarList a)) | | type TVarList a = TVar (TList a) | data TList a = TNil | TCons a (TVarList a) | | Thanks, Joel | | -- | http://wagerlabs.com/ | | | | ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] Re: TChan implementation: Why TVarList
Well, I meant more like TVar [a] but I see that you are pulling from the front and appending to the rear. I need to implement a mailbox where messages can be pulled out based on a predicate or in order of arrival. I'm thinking of using a Map keyed on ClockTime. Do you have any suggestions? Thanks, Joel On Dec 6, 2005, at 11:31 AM, Simon Peyton-Jones wrote: The mutable cell is in the tail. A [TVar a] would be quite different. You can read about a very similar impl (based on MVars) in the original Concurrent Haskell paper (on my papers page) -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
RE: [Haskell-cafe] Re: TChan implementation: Why TVarList
sounds as if you need a priority queue, so you can say give me the message with the earliest time but otherwise yes. Simon | -Original Message- | From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Joel | Reymont | Sent: 06 December 2005 11:46 | To: Simon Peyton-Jones | Cc: Haskell Cafe | Subject: [Haskell-cafe] Re: TChan implementation: Why TVarList | | Well, I meant more like TVar [a] but I see that you are pulling from | the front and appending to the rear. | | I need to implement a mailbox where messages can be pulled out based | on a predicate or in order of arrival. I'm thinking of using a Map | keyed on ClockTime. | | Do you have any suggestions? | | Thanks, Joel | | On Dec 6, 2005, at 11:31 AM, Simon Peyton-Jones wrote: | | The mutable cell is in the tail. A [TVar a] would be quite different. | You can read about a very similar impl (based on MVars) in the | original | Concurrent Haskell paper (on my papers page) | | -- | http://wagerlabs.com/ | | | | | | ___ | Haskell-Cafe mailing list | Haskell-Cafe@haskell.org | http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: TChan implementation: Why TVarList
I think I could fake it on top of Data.Map keyed on ClockTime. findMax :: Map k a - (k, a) O(log n). The maximal key of the map. This would give me the maximum key which I can then proceed to remove. On Dec 6, 2005, at 12:35 PM, Simon Peyton-Jones wrote: sounds as if you need a priority queue, so you can say give me the message with the earliest time but otherwise yes. -- http://wagerlabs.com/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Re: TChan implementation: Why TVarList
Hello Joel, Tuesday, December 06, 2005, 2:46:24 PM, you wrote: JR I need to implement a mailbox where messages can be pulled out based JR on a predicate or in order of arrival. I'm thinking of using a Map JR keyed on ClockTime. JR Do you have any suggestions? it depends. what is the usage scenario? -- Best regards, Bulatmailto:[EMAIL PROTECTED] ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
